Assessment of individuals with profound disabilities is problematic, particularly when traditional approaches are used. As a result, alternate assessments have been attempted that better suit the needs of these students. One approach that has shown some promise is biobehavioral state assessment. Initially used with infants without disabilities, this technique involves measuring overt behaviors and physiologic indices. Its modification and use with students with profound disabilities has potential educational implications because it allows for determining the interaction between behavioral state and environmental variables. This article provides a review of the literature on biobehavioral state assessment of infants as well as adaptations of this procedure for students with profound disabilities. (Contains 2 figures.)